Modular Synthesis of 5‐Substituted Furan‐2‐yl C‐2′‐Deoxyribonucleosides and Biaryl Covalent Base‐Pair Analogues

Abstract

AbstractA modular and efficient synthesis of 5‐(hetero)arylfuran C‐2′‐deoxyribonucleosides was developed. Friedel–Crafts C‐glycosidation of 2‐bromofuran with toluoyl‐protected methyl 2′‐deoxyribofuranoside in the presence of BF3·Et2O gave 5‐bromofuran C‐nucleosides, which were used as key intermediates for Stille or Suzuki coupling with (hetero)arylstannanes or boronic acids to afford a series of 5‐(hetero)arylfuran C‐nucleosides. 5‐Boronofuran C‐nucleoside was prepared by the Suzuki coupling of bromofuran with bis(pinacolatodiboron) or by Ir‐catalyzed C–H borylation of furan and was used for cross‐coupling with 5‐bromoheteroaryl C‐nucleosides to furnish novel covalent analogues of nucleoside pairs. The title 5‐arylfuran C‐nucleosides possess interesting fluorescence properties that may be applicable for fluorescent labeling of biomolecules.